Over 60 million Americans are affected by snoring and/or obstructive sleep apnea (OSA). During normal waking hours, muscle tone in most individuals unconsciously maintains the tongue, pharyngeal folds, soft palate, uvula, epiglottis and posterior pharyngeal wall in adequate spatial relationships so as not to interfere with the free passage of air. However, when asleep in the supine position, gravity can cause the tongue, soft palate, uvula, and epiglottis to move back toward the posterior pharyngeal wall. As a result, the size of the upper airway can be reduced and snoring may occur. Moreover, snoring may also be a sign that a person is suffering from OSA.
OSA is a condition where a person temporarily stops breathing for a short amount of time (10 seconds or longer) due to the blockage of the airway. During a customary sleep period a person suffering from OSA can experience hundreds of so called apneatic events, that is, periods when the person's airway becomes blocked until the patient's hypoxia becomes severe enough that the person awakens and resumes breathing normally again. Not only do these apneatic events cause a deficiency of restful sleep but, due to depleted oxygen levels, possible long term health problems, such as pulmonary hypertension, heart failure and stroke, can result.
One common non-invasive treatment approach for OSA is the use of a continuous positive airway pressure (CPAP) machine. A CPAP machine uses a nasal mask, harness or other headgear to continuously deliver pressured air directly to the person's windpipe, and the positive pressure prevents the upper airway from collapsing during sleep. While proven effective, most CPAP users often suffer from at least one of the following side effects: claustrophobia, difficulty exhaling, inability to sleep, nasal congestion, sore eyes, sore or dry throat, headaches, abdominal bleeding, chest muscle discomfort, nosebleeds and mask-related problems such as rash, skin abrasions and conjunctivitis from air leakage. Additionally, and especially during the early stages of usage, some people may have difficulty adjusting to both the mechanism and/or sound of the machine.
Alternatives to the CPAP machine include devices which can lock the tongue in a fixed position, such as metallic or hard plastic clips. However, these devices risk pain and injury to the tongue as well as are unsuited for self administration. Another alternative to the CPAP machine are mouthpieces that are effective to create an enlarged airway and/or hold the tongue in a fixed position using some type of retainer. While mouthpieces have had some success, normal swallowing can be interrupted, causing a reduction in the clearance of airway secretion, saliva aspiration, and even gastric reflex. Further, a mouthpiece may also cause temporomandibular joint pain to occur and can be detrimental to the normal bite relationship of the dental arches, since it distorts the relationship of the upper and lower jaws. More recently, some mouthpieces have attempted to use a vacuum to hold the tongue, or a portion thereof, in the retainer. However, these devices are often cumbersome and distracting to the sleeping patient. Further, should the patient swallow, the vacuum is broken and the tongue is pulled out of the retainer, resulting in an airway obstruction and a high degree of patient discomfort.
OSA can also cause problems for patients being treated for pulmonary and/or cardiac arrest, or patients undergoing general anesthesia. Typically, these patients are ventilated with a facemask that covers the nose and optionally the mouth. When the patient is under anesthesia or otherwise unconscious, however, the facemask can supply air, oxygen, or other gases to the patient only if the airway remains open. OSA can cause a closure of the airway due to the tongue falling back against the pharyngeal wall, thus preventing proper ventilation of the patient. Even for patients who do not have OSA, upper airway obstructions may develop once the patient is sedated. One solution for maintaining an open airway in patients is to use an endotracheal tube. This approach requires a rigid laryngoscope blade to be inserted into the patient's mouth. The endotracheal tube is then placed down into the trachea thereby holding the tongue away from the posterior pharyngeal wall. While this solution can be effective, successful intubation depends on deep sedation, muscle relaxation, strong analgesia and painful laryngoscopy. Intubation also is very uncomfortable, potentially causing the patient to suffer from a sore throat, as well as causing potential causing damage to the teeth, lips, tongue, vocal cords, and trachea. To terminate the general anesthesia, the patient has to be extubated, which also causes problems. During the critical period of extubation, the patient may develop tachycardia, hypertension, laryngospasm, hypoxia, nausea, vomiting, and even aspiration. Additionally, the patient may need to stay in the recovery room for a long period of time due to intubation and extubation.
More recently, one other solution has been the use of a laryngeal mask airway (LMA), which is inserted blindly into the pharynx and forms a low pressure seal around the laryngeal inlet. The complications from using LMA are similar to those using endotracheal tube. The sore throat resulted from using LMA may even worse than that from endotracheal tube intubation. While tracheal tubes and LMAs can be effective in maintaining an open airway in patients undergoing anesthesia or patients who otherwise having difficulty maintaining an open airway, these devices tend to be obtrusive, time-consuming, and uncomfortable. There are also potential complications that can result due to the use of these devices.
Accordingly, there remains a need for improved, non-invasive treatment methods and devices that are effective to remove upper airway obstructions, reduce or eliminate snoring and/or apneatic events and the related complications, and improve the patent's sleeping quality. There also remains a need for improved, non-invasive treatment methods and devices that are effective to maintain an open upper airway during anesthesia or other medical procedures and conditions in which it is necessary to maintain an open airway.